User interfaces of software applications are typically relatively static, possibly changing their layouts in response to window resizes, but without significant changes in response to the content that is currently being displayed. This is particularly problematic for media player applications, where the visual presentation of the media item—including any user interface components displayed in association with the media item itself—may significantly influence the user's viewing experience. For example, distractingly bright user interface components could detract from the viewing of the media item itself, as could user interface components with colors that “clash” aesthetically with the content of the media item. Adjusting or optimizing user interface components to avoid a negative viewing experience presents a technical challenge, because a media player may be used by thousands, millions, or more users to view thousands, millions, or more media items.